this 'installation directory' cannot be altered, and
proceeding with install causes installer to crash.

temporary fix:

Before running MySQL-python-0.9.2.win32-py2.1.exe,
add an entry to your register base :[HKEY_LOCAL_MACHINE\SOFTWARE\Python\PythonCore\
2.1\InstallPath], and for the 'Value data' of this default
key, provide the path where python.exe is installed at.
For example: D:\plone\Python